Restoring means for automatic switches



Dec. 16, 1 24- 1,519,343

A. H. ADAMS RESTORING MEANS FOR AUTOMATIC SWITCHES Filed Jan. 18 1922 amM.

INVENTOR BY [mi (ii-WV ATTORNEY Patented De ARTHUR H. ADAMS, OFLAKEVILLE, CONNECTICUT,

PATENT OFFICE.

nssrenon 'ro THE NORTH nLno- TBIG MANUFACTURING COMPANY, OF GALION,OHIO, A CORPORATION OF OHIO.

T all whom it may Application filed. January 18, 1922. Serial No.530,135.

Be it known that I, ARTHUR H. ADAMS, a citizen of the United States,residing at Lakeville, in the county of Litchfield and State ofConnecticut, have invented certain new and useful Improvements in Meansfor Automatic Sw tches,

the following Restoring of which is a specification.

My invention relates to automatic s vitches of the two motion type suchas are used 111 automatic telephone exchanges, and particularly to meansfor restoring the switch to its normal position when released. Switchesof this character are provided with a large number of accurately alignedterminals with which movable switch elements, commonly termed wipers,contact. Electromagnetic means is provided to move the wipers intooperative engagement with the desired terminals, the wipers being heldin this position by a latch. Upon the release of this la'tch, the wipersare restored to normal through the in the force of gr In switchesstrumentality of a spring and avity.

where the wipers have two components of motion at right angles, in

order ternnnals,

to reacha large number of contact considerable difficulty has beenexperienced in arranging spring restoring means so as not to produceinequality of pressure between the wipers and terminals in differentparts of the contact bank sufficient to impair the operation of theswitch. In the first rows of the contact bank, the contact between thewipers and fixed terminals electrical connection is established, whilethe wipers may perhaps bind or last rows of the bank. restoring means,

stick to the terminals in the With the usual spring a rather delicateadjustment of the switch Wipers is required on account of the restoringspring.

It is the ob variation in the tension of the ect of my invention to provide improved restoring means for a machine element motion. A furtherobject having two components of 18 to provide an automatic switch of thetype described with spring restoring means wh ch will not cause thewipers an stick together.

d; fixed terminals to bind or My invention may be readily comprehendedfrom a consideration of the switch structure disclosed in theaccompanying drawing which illustrates an automatic switch embodying apreferred form of the invention.

Referring to the drawing, the switch comprises a series of fixedterminals, 1, assembled into a semi-cylindrical contact bank, 2, andmovable wipers, 3, carried by the shaft, 4, and adapted to contact withthe fixed terminals of the bank. Other wipers, 5, may be provided uponthe shaft, 4, and adapted to contact. with a second terminal bank, 6.The shaft, 4, is mounted for rotary and longitudinal movement insuitable ball-bearings, such as 7, in the switch frame. The terminalbanks, 2 and 6, are carried by the frame in fixed relation to thewipers, 3 and 5. Secured to or integral with the shaft, 4, is theratchet, 8. Mounted on the shaft, 4, are the longitudinal ratchet, 9,and the latch rack 10, adapted to move longitudinally with the shaft, 4,but not to rotate therewith. A ratchet pawl, 11, operated by anelectromagnet (not shown) is adapted to engage the ratchet, S, to rotatethe shaft and wipers. A similar paw, 12, co-operates with the ratchet,9, to lift the shaft and wipers vertically, it being understood. thatthe number and spacing of the teeth upon the ratchets 8 and 9,corresponds with the number and spacing of the rows and the contacts perrow in the contact banks, 2 and 6, so that the wipers, 3 and 5, may berotated into alignment with a desired row and then raised intoengagement with any desired contact of the row. A latch, 13, co-operateswith the rack, 10, to maintain the wipers in the actuated position untilthe latch is released by an electro-magnet or other means.

Rot-atably mounted upon the shaft, 4, is a collar, 14-, adapted to havea. slight lost motion or play along the shaft as shown. Attached to thiscollar is a coiled spring, 15, the other end of which is fixed to theshaft, 4. A pin, 16, projects from the collar, 14, and co-operatcs withan upstanding rod, 17, mounted in a switch frame parallel to the shaft,4. The points of attachment of the gularly displaced around the shaft soas to provide a component of spring tension tending to twist the collarand thereby to hold the pin, 16, in engagement with the guide rod, 17.

In the operation of the switch, it will be seen that the top of thespring, 15, will be twisted still further around the shaft while thelower end of the spring is held practically stationary. To avoidincreasing the longitudinal component of the spring tension, I permitthe collar, 14, to have considerable longitudinal play along the shaft.A broken rod, 18, is inserted in the convolutions of ,the spring, 15, toprevent the latter from twisting into a helical shape about the shaft.In the vertical movement .of the wipers, the collar, ll, is carriedalong by the shaft, 4, and there is no change in the relation ofthespring to its associated elements.

Supposing the switch has into 0 e-rative position as described above,with tile wipers, 3 and 5, in engagement with certain contacts in theterminal banks, 2 and 6, when return of the switch to normal is desired,:the latch, 13, is removed from engagement with the co-operating toothon the rack, '10. The weight of the shaft and wipers carries themvertically downward until the wipers clear the bottom contacts of thebank, whereu on the rotary component of the tension 0 the spring, 15,returns them to the normal position shown,

It will be apparent that the rotative force of the return spring 15depends upon the tension of the spring and the amount of twist betweenthe ends of the spring with respect to the shaft. This is the forcewhich tends to cause binding of the wipers upon the bank contacts. Onaccount of the length of the spring 15 and the fact that its tension ishardly changed when the wipers are rotated from the first to the lastrow, tative force upon the wipers does not vary appreciably in differentparts of the contact bank. Accordingly the tendency of the wipers tobind or stick u on the contacts in the last rows "of the bank ismaterially reduced, as it is possible to adjust the switch for adefinite rotary tension but not for a widely varying tension.

do not consider my invention to be limit ed to the precise embodimentherein shown and described, as it may be applied to other devices of asimilar nature, and various modifications will suggest themselves tothose skilled in the art.

I claim:

1. 'In combination, a frame, a shaft mounted for longitudinal and rotarymovement therein, shaft. means engagingthe collar to limit its rotationin one'clirection with respect to the frame, and a helical coiled springfastened been brought a collar rotatably mounted on the to said collarand shaft, the points of at tachment of said spring to the collar andshaft being twisted with respect to the shaft to provide a rotary comonent of force.

2, In combination, a ramem shalt mounted therein, means for rotating theshaft, means for moving the shaft longitudinally, and restoring meansfor the shaft WW ing a helical coiled spring attached thereto and a rodinserted within the convolutions of the spring.

3. In combination, a frame, a shaft mounted therein for rotary andlongitudinal movement, a collar rotatably mounted on the shaft, saidcollar having .a limited amount of play along the shaft, means forlinutin the rotation of the collar on the shaft wit respect to theframe, andahelical coiled having its ends attached to the collar theshaft re ctively.

4. In com ination, a shaft, means for rotating the shaft, means formoving the shaft longitudinally, a non-rotatable element ads:- cent saidshaft and means for restoring e shaft comprising a helical coiled springhaving one and secured to said shaft and the other end secured to saidnon-rotatable element the ends of said spring being twisted with respectto the shaft to provide a rotary component of force.

5. In a switch of the type described, a plurali of fixed terminalsarranged in yertical an' horizontal planes, a movable switch wiper,actuating means for moving said wiper into engagement with any of saidterminals, and resiient means acting with substantially uniform tensionupon said wiper to restore it to normal.

6. In a switch of the type described, a vertical shaft, means forrotating the shaft, means for moving the shaft vertically, a

wiper on said shaft, a plurality of fixed terminals arranged inrows inthe path of said wiper, and means for rotatlng the shaftback to itsnormal position compris ng a helical coiled spring secured to said shaftand arran d to exert a substantially uniform rotatrve tension thereon.

In a switch of the type described, a vertical shaft, means for rotatingthe shaft, means for movin the shaft vertically, a wiper on said sha t,a plurality of fixed terminals arranged in rows in the path of san!wiper, a movable member adapted to move vertically with said shaft butnot to rotate therewith, and restoring means for the shaft comprisin r acoiled spring secured to said shaft an said movable member and arrangedto exert a substantially uni-form rotative tension upon the shaft.

8. In a switch of the type described, a frame, a vertical shaft therein,means for rotati-ngthc shaft, means for moving the shaft vertically, awiper on said shaft, a plurality of fixed terminals arranged in rows inthe path of said wiper, a collar rotatably mounted on said shaft andhaving a limited amount of vertical play thereon, means for limiting therotation of said collar in one 5 direction with respect to said frame,and a helical coiled spring attached to said shaft and said collar, thepoints of attachment be- ARTHUR H. ADAMS.

